PB2310: VALUE OF PLATELET SURFACE GP IIB-IIIA AND BLEEDING QUESTIONNAIRE IN IDENTIFICATION OF EGYPTIAN PATIENTS WITH GLANZMANN’S THROMBASTHENIA
Authors: L. Saleh, D. Ali, M. Sarhan, H. Azzam
Journal: HemaSphere (2022)

Background: Patients with inherited platelets disorders are characterized by a prolonged clinical history of mucocutaneous bleeding. Glanzmann’s Thrombasthenia (GT) is an autosomal recessive inherited platelet disorder, characterized by prolonged bleeding time, normal platelet count, and absence of platelet aggregation in response to all platelet agonists except for ristocetin. Although Glanzmann’s thrombasthenia is usually considered to be a rare disorder, it can be almost as frequent as hemophilia and von Willebrand disease in regions where consanguinity is common, such as Indians, Iraqi Jews, Arabs and Iranians. GT has been subclassified into types I, II, and III. Patients with less than 5% of normal GPIIb/IIIa are classified as type I and 5–20% as type II. Type III variants usually have dysfunctional receptors with near-normal GPIIb/IIIa levels. Bleeding severity is unpredictable in GT. Some patients never have serious bleeding and others are free of bleeding complications. Although, it is clear that GT is associated with significant bleeding, the relation between types of GT and bleeding score remains unclear. Aims: this study was designed to evaluate glycoproteins IIb-IIIa levels (CD41and CD61) by flowcytometry on the platelet surface of patients with GT in addition to bleeding score for proper typing and bleeding assessment of Egyptian patients with GT. Methods: All the patients and their parents/guardians were subjected to a bleeding questionnaire to assess their bleeding score developed by ISTH/SSC-BAT (Bleeding assessement tool) and were investigated for platelet surface receptor GPIIb-IIIa (CD41 and CD61) by using flow cytometry. Results: Our study included 16 pediatric patients with GT, 31% of GT patient families have consanguineous marriages. On subgrouping our patients according to CD41 and CD61 levels, most of our patients exist in the type 1 group 11 patients (68.8 %) with absent or extremely reduced levels (<5%) of CD41 and CD61. Three (18.8%) patients were categorized as type II with median CD41 levels of 11.3% and median CD61 levels of 28.6%. Two (12.4%) patients exhibited a normal or near-normal amount of CD41 and CD61 (median: 95%). The analysis of data showed that most of our patients with GT had mild and moderate bleeding episodes (62.5 and 31.3%, respectively), while severe bleeding only represents 6.2%. The commonest form of bleeding in our patient was epistaxis and cutaneous bleeding representing 94% followed by oral cavity bleeding, tooth extraction bleeding and bleeding after surgery representing 50% then bleeding from minor wound, gastrointestinal bleeding and hematuria (25, 19 and 6% respectively), no patients had menorrhagia. Summary/Conclusion: flow cytometry should be used as an important tool in the screening and typing of GT patients. Type I GT is the most common type in our patients with lowered mean CD41 expression in comparison with CD61.No significant correlation was found between different forms of bleeding and percentage CD41,CD61 and double expressing platelets.